‘The Diplomat’ Creator on Kate and Hal’s Marriage and Season 3’s Horrifying Last-Minute Twist: ‘There’s Nothing a Character in This Show Does That We Can’t Justify’

Initially, Grace Penn (Allison Janney) is confronted with two shocking revelations: she’s the new president of the United States due to the unexpected death of former President William Rayburn (Michael McKean), and she learns that Rayburn suffered a heart attack while speaking to Hal. This implies that Hal called to warn about a secret that Grace, the untrusted Vice President, orchestrated: the bombing of the HMS Courageous, resulting in the deaths of 41 British sailors.

Abreast with this information, Grace’s wrath is primarily directed at Kate (the messenger) and largely because she has always resented Kate for aiming at her position. Consequently, rather than appointing Kate as her Vice President, Grace selects Hal.

This decision triggers turmoil in the Wyler household (or, should I say, estate, as they reside at Winfield House in England). Hal, who adores his intelligent wife, offers to decline the vice-presidency for Kate’s sake. However, amid her fury, Kate urges him to accept it (she’s seemingly left with no alternative).

Hal is also in a difficult position, understanding how painful this situation is for Kate, now relegated to the thankless role of Second Lady instead of Ambassador to England, where she was well-regarded.

In a nutshell, Grace is inaugurated, and Kate bids farewell to her embassy staff before she and Hal proceed to the airport. When Hal boards the plane, Kate stands behind on the tarmac, tears brimming in her eyes. They share a moment, locking eyes, but ultimately, Hal boards, leaving Kate behind.

Months later, Hal surprises Kate for their anniversary, but he’s hit with an unexpected shock when he finds out that she’s involved with a young MI6 agent, Callum Ellis (Aidan Turner), seeming to have moved on.

They share a bedroom for appearances, leading to an argument when Hal confronts Kate about her affair. Their agreement to maintain a marriage on the surface while being separated secretly intensifies her rage. Kate also expresses how Hal’s decision to accept the VP role has affected their love life, triggering a breakdown in a quiet den as she curls up on the rug in tears.

Simultaneously, CIA station chief Eidra Park (Ali Ahn) learns from a reliable source that a Russian official suspects American involvement in the bombing of the HMS Courageous. The news threatens to make its way into public knowledge. Together, Kate, Hal, and Eidra travel to meet Grace Penn at her residence in Amagansett, Long Island. They encounter Grace’s resentful husband, Todd Penn (Bradley Whitford) who despises his First Lady role and doubts his wife and the new VP.

As the discussion unfolds, Grace, Hal, and Chief of Staff Billie Appiah (Nana Mensah) worry about the inevitable leak concerning Grace’s part in the bombing. They decide to bring British Prime Minister Trowbridge (Rory Kinnear) to Amagansett, planning to reveal the Russian source and admitting Grace’s involvement. They hope to secure his silence by promising U.S. assistance with Britain’s financial crisis in exchange for a press conference where Trowbridge will announce that Margaret Roylin (Celia Imrie), Trowbridge’s close aide who committed suicide in U.S. custody earlier this season, was behind the bombing.

Kate recognizes the disastrous implications of this plan, realizing Trowbridge would be outraged upon discovering any American connection to the bombing. When she tries to warn Grace, Billie dismisses her, sending her back to England. In a moment of desperation, she confides in Todd Penn that instead of implicating Grace, they should say Rayburn was responsible since he is no longer alive, thus preserving Grace’s presidency.

Todd grasps the significance of her plan and finds a means for Kate to remain, despite her adverse reputation. Trowbridge arrives with his advisor, Austin Dennison (David Gyasi), and they reach an arrangement: Trowbridge, in exchange for U.S. financial support, will name Margaret as the mastermind behind the bombing. However, just before the press conference, Trowbridge contradicts expectations, revealing that President Rayburn was the orchestrator of the bombing, triggering chaos.

Meanwhile, protests against the U.S. erupt outside the consulate, while Kate finds herself trapped in the estate with Callum. He informs her of a more pressing issue: a Russian submarine has allegedly sunk near England, carrying the mythical super weapon, Poseidon, believed to be capable of mass destruction. Their argument about decision-making reveals Kate’s growing realization that she’s repeating her past mistakes by being involved with a man too similar to Hal.

As things escalate, Kate recognizes something must be done to prevent China or Russia from seizing the sub. Callum suggests that Grace needs to apologize to Trowbridge regarding Rayburn’s actions. They need to collaborate to deal with the submarine. Kate attempts to connect with Hal, but he’s unreachable, nor does anyone trust her anymore—except Todd. When escorted off the premises, she jumps into the pool where Todd is swimming, persuading him that Grace should declare Rayburn as responsible for the bombing.

Again, Todd realizes Kate’s idea might salvage his wife’s political career. Although she’s still persona non grata, she remains. During this time, Trowbridge and his advisor arrive, and a deal is struck: in exchange for American assistance, Trowbridge will acknowledge that Margaret Roylin was the mastermind. However, the situation spirals out of control during the press conference when Trowbridge goes off-script, implicating President Rayburn, igniting national outrage.

Facing backlash, Kate ultimately barricades herself at the manse with Callum, who relays to her the reality surrounding the Russian submarine incident—and the Poseidon weapon believed to be on board. Their discussions reveal their mutual frustrations and miscommunications, leading Kate to realize that she has once again fallen for a man reminiscent of her husband.

Yet, there’s a pressing need to address the submarine situation before other nations intervene. Callum asserts that Grace needs to seek forgiveness from Trowbridge. Meanwhile, when Kate speaks with Hal, he facilitates a meeting between Grace and Trowbridge in England. Grace refuses to apologize but offers to assist with the submarine. At the meeting, Trowbridge is disinterested and storms out, doubting Grace’s claims about the Poseidon.

Striving to substantiate Grace’s claims, Kate attempts to persuade Callum to aid at the meeting, but Hal objects, wanting to keep Callum close to Kate. Subsequently, Kate devises a plan: to send an American submarine secretly to capture images of the Russian submarine suspected to be housing the Poseidon.

Despite Grace’s initial reluctance, Hal confers with her about a plausible plan, leading her to agree. Later that night, Callum visits Kate, but she rebuffs him, hinting at a shift in her feelings. During another meeting with Trowbridge, Grace reveals photos of the submarine but still faces rejection. It’s then that Hal encourages Kate to speak, subtly indicating a pre-arranged tactic. She proposes to Trowbridge to enshroud the Russian submarine, and he acquiesces. This new understanding between Kate and Hal reignites their previously electrifying partnership.

Shortly thereafter, Kate breaks down emotionally, pleading for Hal to forgive her, and he does. She realizes she is ready to return to Washington with him, leaving her role in England behind.

Just as their cars are being packed, Callum informs Kate that he suspects the Russians have taken the super weapon, as radiation levels near the submarine have significantly dropped. In disbelief, Kate alerts Hal, who rushes off presumably to inform Grace.

At that moment, Todd approaches Kate and questions her feelings regarding Hal and Grace’s connection. Although she initially brushes it off, she watches Hal and Grace closely, realizing that the casualty of her suspicions was not Russia, but rather Hal and Grace using her to facilitate their own plans.

She confronts Hal, piecing the situation together, highlighting that this union could lead to accusations of war from Britain towards Russia. Notably, Hal has used her to convince Trowbridge to bury the submarine, tying her into an elaborate scheme she wasn’t originally aware of.

Hal commands Kate to remain silent and goes to address Grace. When she inquires if everything’s alright, Hal confirms, “She knows.”

“Kate is a chaotic figure this season,” I mention to Cahn as we kick off our conversation (which unfortunately went unrecorded). She giggles and remarks, “Kate has always been in disarray.”

I inquire, “So why did she choose to involve herself with Callum? Why not with Dennison?” Cahn bursts into laughter as I call Callum “a jerk” and recounts a recent interview where someone suggested Kate had “mental illness.”

“This bothered me,” said Cahn. “I created a character who’s bipolar in ‘Homeland’—that applies medically. Yet I’ve never suggested Kate has a mental issue.” She notes that “men often perceive Kate as unstable, whereas women think Callum isn’t a good person.”

Despite this, I still stand by Team Hal, equating it to Paul Newman’s sentiments about Joanne Woodward: why settle for a hamburger when you can enjoy steak? I press further, questioning Kate’s inconsistent feelings—encouraging Hal to accept the VP role only to later lament the downfall of their marriage due to that very choice. I ask Cahn for clarity.

Cahn responds, “When Kate reached the airport and stepped onto the tarmac, it hit her hard. She couldn’t find the strength to move on. Hal could have come back down, suggested they discuss things, but instead, he stepped onto the plane.”

“That’s a valid point. Then why didn’t Kate have her fling with Dennison?” I ask Cahn.

“You nurture characters as they evolve, like monitoring a garden,” she explains. “Dennison became a moral lodestar in the story, acting as a counterbalance to Trowbridge and Kate. His career matters too much for him to jeopardize it by engaging in a relationship with someone who is merely visiting. But he was also significant for Kate to weigh against Hal, whose moral choices she has conflicted feelings about.”

“And then why Callum?” I press.

Cahn reflects, “Hal has been Kate’s anchor for years. In this division of their lives, during a separation, everything fractures. People often subconsciously seek familiar traits in new partners, wanting to believe they’re pursuing perfection without the mistakes. Those flaws, however, are part of what defines a person.” She illustrates this with her palm, flipping it to symbolize differing perspectives. “True love is unsightly; it’s akin to addiction in all forms.”

Frustrated, I respond, “It infuriates me that after realizing Callum is unsuitable, she then crawls back, seeking a second chance. She’s portrayed as strong.”

Cahn suddenly looks startled, lifting her hand to her mouth and exclaims, “Oh my God, Trish!” After a moment of realization, she states, “I think I’ve been subconsciously narrating my parents’ relationship!”

She recounts, “My mom wanted to leave, my dad was devastated. I understood her choices, though my dad didn’t. Their later attempts at dating each other were eye-opening for me.”

“I see parallels between Kate’s journey and my mother’s: both navigating life’s difficult choices,” she concludes, reflecting on the bravery necessary for exploration and personal growth.

As our interaction nears its conclusion, I pose one final question about Hal. Did he manipulate Kate for the super weapon? Was his love false?

Cahn clarifies, “While Hal utilized Kate to navigate the situation with the submerged submarine, he genuinely wishes for their reunion. Hal’s endeavored to release her. I empathize with him deeply; he’s worked tirelessly to let Kate go.”

“But is he corrupt?” I challenge.

“Every character’s decision is one we can rationalize,” Cahn affirms.